DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Remarks
The amendments and remarks filed on 04/30/2025 have been entered and considered. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior office action. The rejections and/or objections presented herein are the only rejections and/or objections currently outstanding. Any previously presented objections or rejections that are not presented in this Office Action are withdrawn. Claims 1, 5, 7-10, 13, 15-24, 26, and 28-32 are pending; Claims 2-4, 6, 11-12, 14, 25, 27, and 33-34 are cancelled; Claims 1 and 15 are amended; Claims 15-24 are withdrawn; and Claims 1, 5, 7-10, 13, 26, and 28-32 are under examination.
Withdrawal of Rejections
The rejection of Claims 1, 3, 5, 7-10, 13, 26, and 28-32 under 35 U.S.C. 112 (pre-AIA ), second paragraph in the previous office action is withdrawn due to the amendment to or cancellation of the claims filed on 04/30/2025.
The rejection of Claims 1, 3, 5, 7-10, 13, 26, and 28-32 on the ground of nonstatutory obviousness-type double patenting as being unpatentable over the claims of U.S. Patent No. 12098408 in view of Tolan et al. and Singh et al. is withdrawn due to the Terminal Disclaimer filed by Applicant on 04/30/2025.
The provisional rejections of Claims 1, 3, 5, 7-10, 13, 26, and/or 28-32 on the ground of nonstatutory obviousness-type double patenting over the claims of copending Application No. 17/326442 in view of Burke et al., Tolan et al., and/or Singh et al. are withdrawn due to the Terminal Disclaimer filed by Applicant on 04/30/2025.
Claim Rejections - 35 USC § 112(b), or 112, Second Paragraph
Claims 1, 5, 7-10, 13, 26, and 28-32 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention.
Claim 1 is indefinite due to the recitation of “raw material being 10-30% TS (total solids at 105 oC)” in the feeding step of the claim 1. A parenthetical phrase is akin to “for example”, which render the claim indefinite because it does not clearly indicate if the limitation “total solids at 105 oC” in the parentheses is required or simply an example of the recited 10-30% TS. For purpose of examination, the recited “10-30% TS” is interpreted as being determined at any temperature, not limited to 105 oC. The claim 1 also recites the limitation “an amount of carbohydrates being below 25% by weight in the solid fraction after the last solid-liquid separation stage” near the end of the claim. The claim does not recite any comparison phrase. It is unclear which specific control or benchmark is used for determining the carbohydrates in the solid fraction to be an amount of below 25%. For the purpose of examination, it is assumed that the amount of below 25% is determined by comparison to an amount of carbohydrates in the plant-based raw material that is initially introduced to the first enzymatic hydrolysis stage. In another word, an amount of carbohydrates in the plant-based raw material initially introduced to the first enzymatic hydrolysis stage is set at 100% by weight; and after at least two enzymatic hydrolysis stages more than 75% of the carbohydrates are hydrolyzed (converted) to soluble sugars, with an amount of carbohydrates in the solid fraction being below 25% after the last solid-liquid separation stage.
The remaining claims are rejected for depending from an indefinite claim.
Claim Rejections - 35 USC § 103
Claims 1, 5, 7-10, 13, 26, 28-30, and 32 are rejected under 35 U.S.C. 103 as being unpatentable over Tolan et al. (WO 2007/147263, 2007, cited in IDS) and Foody (US Patent No. 4461648, 1984, of record, incorporated by reference by Tolan et al.), as evidenced by Tolan-2 et al. (US 2010/0184151, 2010, of record).
Examiner notes that the disclosure of Foody is a part of the disclosure of Tolan et al., because Foody is incorporated by reference to Tolan et al. (see para. [0072] of Tolan et al).
Tolan et al. teach a method for enzymatic hydrolysis of cellulose from a pretreated lignocellulosic feedstock (i.e. plant-based material) (abstract, para 0034), and indicate that sugars/carbohydrates present in the liquid fraction are competitive inhibitors of enzymes and cause product inhibition, and their method comprising two enzymatic hydrolysis stages overcomes this disadvantage, specifically: the two enzymatic hydrolysis stages, involved with intermittent removal of a liquid fraction containing the competitive inhibitors in a solid-liquid separation stage after a first enzymatic hydrolysis stage, supply only a solid fraction to a second enzymatic hydrolysis stage, which significantly improves yields of sugar production in the enzymatic hydrolysis process, and is more efficient when compared to an uninterrupted one-stage enzymatic hydrolysis; and Tolan et al. further teach another advantage of their method, specifically: the enzymes attached to the solid fraction is recycled back to the enzymatic hydrolysis step, thus reducing enzyme amounts needed for the enzymatic hydrolysis process and making the process less costly (abstract, para 0053, para 0011/lines 6-11, page 4/lines 23-25, page 5/lines 4-5).
Overall, Tolan et al. teach the method comprises steps: (a) feeding the pretreated lignocellulosic feedstock to a hydrolysis tank in a first enzymatic hydrolysis stage, adding enzymes to the feedstock, and hydrolyzing celluloses of the feedstock, wherein the enzymes comprise cellulase and glucosidase; (b) subjecting the hydrolyzed feedstock to solid-liquid separation in a first solid-liquid separation stage after the first enzymatic hydrolysis stage, separating by microfiltration a liquid fraction comprising carbohydrates from a solid fraction comprising unhydrolyzed fiber and lignin, to which the enzymes are bound/absorbed, wherein the liquid fraction and the solid fraction are recovered; (c) re-suspending the solid fraction in an aqueous solution to producing a re-suspended slurry (Note: this step comprises diluting and mixing the solid fraction with the solution), and hydrolyzing the resuspended solid fraction in a second enzymatic hydrolysis stage to continuously hydrolyze the celluloses by the enzymes that are absorbed/bound to the solid fraction, recycled from the first enzymatic hydrolysis, without adding any additional enzymes (Note: these teachings meet the limitations about supplying enzymes absorbed to a solid fraction to a second or latter enzymatic hydrolysis stage without adding additional enzymes, recited in the supplying step of Claim 1); (d) subjecting the hydrolyzed feedstock from the second enzymatic hydrolysis stage to solid-liquid separation in a second solid-liquid separation stage, and separating a liquid fraction comprising carbohydrates from a solid fraction comprising lignin; and (e) subjecting the solid fraction comprising lignin from the second solid-liquid separation stage to a lignin processing, where the lignin is removed/recovered separately (reading on “a lignin separation stage” in the instant claim 13) (paragraphs 0027, 0034, 0103-114, 0118-119, Fig. 1A, Example 1/paragraph 130, Example 2/paragraphs 0133-0136); wherein lignin, as a byproduct of cellulose conversion, can be used as a fuel to power the process, to replace fossil fuels (paragraph 0003); and wherein the lignocellulosic feedstock is non-woody plant biomass or wood-based material/forestry biomass, such as recycled wood pulp fiber, sawdust, hardwood, aspen wood, softwood, and a combination thereof (paragraphs 0066/lines 9-10 and 0004) (Note: these materials reading on the claimed “wood based, cellulose based material” in the pretreating step of claim 1). Examiner notes that the second solid-liquid separation stage taught by Tolan et al. read on the “last solid-liquid separation stage” recited in the claims 1 and 13, because the method taught by Tolan et al. comprises only two stages. Regarding the residence time ranges of the first and second enzymatic hydrolysis stages recited in Claim 1, Tolan et al. further teach the residence time in the first enzymatic hydrolysis stage is in a range from about 12 hours to about 24 hours for partially hydrolyzing the feedstock (para 0105, Claim 54). Tolan’s use of the modifier “about” indicates a precise residence time is not required for operability of the first enzymatic hydrolysis stage. As such, the residence times taught by Tolan include those residence times being less than 12 hours. Thus, the residence time range of Tolan overlaps with the claimed range “more than 8 hours and less than 12 hours”, rendering the claimed range obvious. See MPEP 2144.05, which states “in the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art,” a prima facie case of obviousness exists. Tolan et al. further teach the residence time in the second enzymatic hydrolysis stage is in a range from about 12 hours to about 200 hours, specifically it can be 24, 30, 36, 42, or 48 hours (para 0119, Claim 53), which either reads on or overlaps with the claimed range “22-48 hours”, thus rendering the claimed range obvious.
Regarding the step of “pretreating the plant based raw material using a combination of acid treatment and steam explosion …” in the claim 1, Example 1 of Tolan et al. expressively teach pretreating lignocellulosic feedstock/straw with a combination of steam explosion and sulfuric acid treatment, in accordance with the teachings of Foody (US Patent No. 4461648), which is specifically incorporated by reference by Tolan et al. (see para 0072/lines 1-3 of Tolan et al.), for facilitating the downstream enzymatic hydrolysis in their method. Tolan et al. also teach that during the pretreating with the combination of steam explosion and acid treatment, the pressure produced by the steam is brought down rapidly with explosive decompression (i.e. the pressure is rapidly released, meeting the new limitation in the pretreating step of claim 1) (para 0008, lines 1-2). Tolan et al. further teach that the steam explosion with acid treatment of sulfuric acid (added to feedstock to achieve a pH range of 0.4 – 2.0 of Foody) had been the standard pretreatment process for two decades; and the resulting pretreated feedstock requires less cellulase enzymes to hydrolyze cellulose than other pretreatment processes (see Tolan et al: paragraphs 0008, 00130/lines 2-4, 0072/lines 1-3).
Example 1 of Tolan et al. differs from the claim 1 in that the example uses straw, not wood-based material, as the feedstock of the pretreating. However, the feedstock in the method of Tolan et al. is not limited to the straw of Example 1, as Tolan et al. expressively teach using wood-based material as the feedstock in their method and these wood-based materials are the most promising for ethanol production (paragraphs 0066/page 16/lines 16-17, 0004/page 1/lines 24 and 27-28); and Tolan et al. specifically indicate that the examples in the disclosure are for illustrative purpose only and they do not limit the scope of the method in any manner (paragraph 00129).
The incorporated reference Foody teaches a method for pretreating lignocellulosic feedstock, wood chips (i.e. wood-based, cellulose-based material), with a combination of acid treatment and steam explosion, wherein the wood chips are soaked in sulfuric acid and then processed with steam explosion, which includes: injecting steam to reach a pre-determined operation pressure and then rapidly releasing the pressure produced by the steam (by closing steam injection valve and opening discharge valve) with explosive decompression, such that the treated feedstock is rapidly depressurized and explosively decompressed to atmospheric pressure; and the pretreatment leads to removing hemicellulose from lignocellulosic material through hemicellulose hydrolysis into oligosaccharides and pentoses (i.e. hemicelluloses degrade into monosaccharides and oligosaccharides, meeting the new limitation in the pretreating step of claim 1), increasing the accessibility of cellulose to biochemical agents/cellulose enzymes, and reducing a degree of polymerization of cellulose, thus facilitating the conversion of feedstock into carbohydrates/glucose (abstract, Example 3, column 10/lines 32-36 and 44-49, column 6/lines 6-8, column 7/lines 50-56, column 12/lines 4-5, column 1/lines 28-36, 40-43, and 48-49). The incorporated Foody also teaches that the use of the acid (as a catalyst) in the combined treatment has the benefits of shorting cook time of the steam explosion and reducing pentose losses (col. 12, lines 4-5). Foody further teach that his invention is applied for reducing inaccessibility of cellulose within hardwood materials (i.e. wood-based material) and agricultural materials such as straw, so as to render the cellulose in such materials more accessible to the attacking by enzymes (col. 1, para. 2).
It would have been obvious to pretreat wood-based plant material with a combination of acid treatment and steam explosion in the method of Tolan et al. for facilitating the enzymatic hydrolysis, because Tolan et al. specifically teach that the wood-based material, such as recycled wood pulp fiber, sawdust, hardwood, aspen wood and softwood, is applied as the lignocellulosic feedstock in their method (paragraph 0066/lines 9-10), and that these wood-based materials are most promising for ethanol production (group 3 in paragraph 0004). Furthermore, the combination of acid treatment and steam explosion had been a standard pretreatment process of lignocellulosic feedstock for decades, as supported by Tolan et al., and techniques have been well established in the art for effectively pretreating wood-based materials by using a combination of steam explosion and acid treatment, as supported by incorporated Foody. Moreover, it had been well known in the art that the pretreatment of wood-based feedstock with a combination of acid treatment and steam explosion effectively hydrolyzes hemicellulose, increases the accessibility of celluloses to treatment agent/enzymes, and reduces the degree of polymerization of celluloses in the feedstock, as supported by Foody. Finally, the pretreatment of wood-based feedstock with a combination of acid treatment with steam explosion has the benefits of shorting cook time of the steam explosion and reducing pentose losses, as well as requiring less cellulase enzymes to hydrolyze celluloses compared to other pretreatment processes,
as supported by Foody and Tolan et al.
Regarding the limitations “the liquid after the first … stage comprising soluble C5 and C6 carbohydrates” (in the first solid-liquid separation step) and “recovering at least 50% of the soluble C5 and C6 … in the first … separation stage” in Claim 1, Tolan et al. teach recovering substantially all of the aqueous phase (i.e. a liquid fraction comprising soluble carbohydrates) obtained from the first solid-liquid separation stage, and sending the aqueous phase to fermentation for ethanol production, wherein the aqueous phase comprises soluble glucose (reading on the C6 carbohydrate recited in the claim 1) (page 35/lines 9-12, page 36/lines 3-4 and 17-18). Thus, Tolan et al. teach recovering substantially all of the liquid fraction comprising soluble carbohydrates comprising C6 carbohydrates in the first solid-liquid separation stage for producing ethanol. Regarding the soluble C5 carbohydrate required by the claimed limitations in claim 1, Tolan et al. further teach that preferably, the pretreatment is employed to hydrolyze hemicellulose in lignocellulosic feedstock, so that nearly complete hydrolysis of the hemicellulose, to monomeric sugars, e.g. soluble C5 carbohydrates including xylose, arabinose, and mannose, occurs; and cellulose hydrolysis to glucose is mainly in subsequent enzymatic hydrolysis stage with cellulase enzymes (page 17/paragraph 0071). Furthermore, soluble C5 carbohydrates, i.e. xylose, arabinose, and mannose (along with C6 carbohydrates/glucose) are inherently present in the lignocellulosic feedstock slurry generated by the pretreatment with the combination of acid treatment and steam explosion in the method suggested by Tolan et al., as evidenced by Tolan-2 et al., who demonstrate that after lignocellulosic feedstock comprising xylan/hemicellulose is pretreated by the combination of acid treatment and steam explosion as described by Foody in Pat No. 4461648 (same as the Foody reference incorporated by Tolan et al.), the resulted lignocellulosic feedstock stream comprises soluble C5 carbohydrates xylose, arabinose, and mannose along with soluble C6 carbohydrates/glucose (see first half of paragraph 0157 of Tolan-2 et al.). In view of the fact that Tolan et al. expressively teach directly transferring the pretreated feedstock slurry generated from the pretreatment to the first enzymatic hydrolysis stage for the enzymatic hydrolysis by cellulase and beta-glucosidase (page 34/lines 10-15), the soluble C5 carbohydrates generated by the pretreatment in the method suggested by Tolan et al. are carried over to the first enzymatic hydrolysis stage and consequently present in the liquid fraction generated from the first solid-liquid separation stage, along with glucose/C6 carbohydrate generated by the enzymatic hydrolysis of cellulose (and the pretreatment). Accordingly, the liquid fraction obtained from the first solid-liquid separation stage in the method suggested by Tolan et al. comprises soluble C5 and C6 carbohydrates. Given that Tolan et al. teach recovering substantially all of the liquid fraction containing soluble carbohydrates in the first solid-liquid separation stage for the subsequent fermentation, the teachings of Tolan et al. meet the requirement of “recovering at least 50% of the soluble C5 and C6 carbohydrates …” in Claim 1. Thus, the teachings of the cited prior art meet the requirement of all the limitations about C5 and C6 carbohydrates in the claim 1.
Regarding the limitation “the liquid fraction after the second or later enzymatic hydrolysis … comprising more than 80% by weight soluble C6 carbohydrate …” in the separation step of claim 1, Tolan et al. teach that sending the fiber solid fraction, obtained from the first solid-liquid separation stage, to the second hydrolysis reactor for further hydrolysis by cellulose enzymes: cellulase and b-glucosidase bound to the fiber solid, in the second enzymatic hydrolysis stage (page 35/lines 12-14, page 36/lines 4-6). As supported by the disclosure of Tolan et al. (page 20/lines 3-4, page 22/lines 12-14), the enzymes of cellulase and beta-glucosidase hydrolyze only celluloses or cellulose fractions and generate only glucose (soluble C6 carbohydrates). As such, the enzymatic hydrolysis in the second enzymatic hydrolysis stage of Tolan et al. generates C6 carbohydrates (glucose), but not any C5 carbohydrates. Given that the liquid fraction comprising the soluble C5 carbohydrates has been removed from the fiber solid fraction in the first solid-liquid separation stage, the fiber solid fraction send to the second enzymatic hydrolysis stage comprises either none or a trace amount of C5 carbohydrates. Accordingly, soluble carbohydrates in the liquid fraction after the second enzymatic hydrolysis in the method suggested by Tolan et al. comprise substantially C6 carbohydrates (glucose) with none or a trace amount of C5 carbohydrates, thus meeting the limitation requirement of more than 80% C6 carbohydrates and less than 20% C5 carbohydrates in the claim.
Regarding the limitation “at least one of the first enzymatic hydrolysis … includes a mixing stage in connection therewith” recited at the end of Claim 1, Tolan et al. teach that re-suspending the solid fraction in an aqueous solution to produce a re-suspended slurry to be hydrolyzed in the second enzymatic hydrolysis stage (i.e. diluting and mixing the solid fraction with the aqueous solution) (page 8/last 2 lines), and that the pretreated feedstock slurry is pumped into a hydrolysis make-up tank along with an aqueous solution of enzymes to mix the feedstock slurry with the aqueous solution (Note: it is diluted during mixing) and then fed to a reactor in the first hydrolysis reactor for enzymatic hydrolysis (page 34/lines 12-16 and 20-24, para 0134/lines 1-3, Fig. 1A, 1B) (note: this process comprises both mixing and diluting the feedstock since additional aqueous solution is added); and the separated solids containing bound enzymes are resuspended/mixed with an aqueous solution or water, and introduced to the second hydrolysis reactor, to produce a re-suspended feedstock slurry, for performing the second enzymatic hydrolysis (paragraphs 00117/lines 2-6 and 8-9, 0118/lines 1-3, 0135/lines 4-6) (note: this process also comprises both mixing and diluting the feedstock). Examiner notes that these mixing stages of Tolan et al. can be considered as mixing stages “in connection therewith” the first or second enzymatic hydrolysis stage, thus meeting the claimed limitation, given they are applied for preparing enzymatic resuspensions to be immediately used in the subsequent enzymatic hydrolysis. Furthermore, Tolan et al. expressively teach that the first and second enzymatic hydrolysis reactions may be carried out in an actively mixed reactor/tank, in which mechanical agitation is carried out during the enzymatic hydrolysis reaction; and the active mixing within the hydrolysis tank may be achieved by impellers or pumps, as is well known in the art (paragraph 0110: last 4 lines). As such, Tolan et al. not only teach a mixing stage in connection with the first and second enzymatic hydrolysis stages (before the enzymatic hydrolysis reactions are carried out), but also teach an actively mixing stage, simultaneously conducted while the enzymatic hydrolysis reactions in the reactor is carried out. Moreover, the incorporated Foody also expressively teaches mixing and diluting the pretreated feedstock with enzyme solutions and acetate buffer, and consistently mixing the mixed feedstock with a rotary shaker during the enzymatic hydrolysis stage (column 10, lines 56-63). Regarding the further limitation “pH is adjusted …” at the end of the claim 1, Tolan et al. teach that prior to addition of enzyme, the pH of the acidic feedstock is adjusted to a value that is suitable for the enzymatic hydrolysis reaction (para 0007/last 5 lines); and Foody also teaches neutralizing the pH of pretreated lignocellulosic material with a suitable base (claims 17, 31-32). The Examiner notes that it is routine in the art to mix lignocellulosic biomass and adjust pH in a liquid solution to a desirable level for performing enzymatic hydrolysis reactions to hydrolyze the biomass, as supported by Tolan et al. and Foody. Thus, the teachings of Tolan et al. incorporated by Foody reference render the limitations about the mixing stage and adjusting pH in the claim 1 to be obvious.
Regarding the newly added limitations of “hemicelluloses are treated … degrade into monosaccharides and oligosaccharides … pressure is rapidly released” recited in the pretreating step of Claim 1, the degradation of hemicelluloses into monosaccharides and oligosaccharides is directed to an inherent feature of a process of pretreating plant-based materials by using a combination of acid treatment and steam explosion. Furthermore, Tolan et al. incorporated by Foody teach the combination of acid treatment and steam explosion degrades into monosaccharides and oligosaccharides, in which pressure caused by steam is rapidly released with explosive decompression, as indicated above. Thus, teachings of the cited prior art meet the claimed limitations.
Regarding the newly added limitation of “a consistency … 10-30% TS (total solids at 105oC) in the first enzymatic hydrolysis stage” recited in the first solid-liquid separation step of Claim 1, Tolan et al. teach that the first enzymatic hydrolysis stage has a total suspended solid content of about 3% to about 30% (w/w) (paragraphs 0044 and 0074), which encompasses the claimed range “10-30%”, thus rendering the claimed range to be obvious (See MPEP 2144.05); and Tolan et al. expressively teach that the total solid content is a content at 105oC, which is determined by drying total solids at 105oC, a process well known in the art (para 0074: page 18/last 2 lines and page 19/lines 1-2). Thus, the claimed limitations would have been obvious over the cited prior art.
Regarding the newly added limitation of “an amount of carbohydrates being below 25 % by weight in the solid fraction after the last solid-liquid separation stage” recited in the second separation step of Claim 1, this limitation describes an amount of solid carbohydrates unhydrolyzed/remained in the solid fraction after enzymatic hydrolysis, and also a conversion rate of solid carbohydrates (i.e. polysaccharide carbohydrates) in plant-based feedstock to soluble sugars in the claimed method, which is in a range of over 75% by weigh (100% - 25% = 75%) given the solid carbohydrates remained in the solid fraction are at an amount “below 25 % by weight”. Examiner notes that the limitation about a rate (over 75%) of converting solid carbohydrates to soluble sugars, or a rate (below 25%) of carbohydrates being unconverted and remained in solid fraction, is directed to an outcome of the claimed method, i.e. it is directed to what the claimed method does to the plant-based feedstock, not to what the what the claimed method is. Although Tolan et al. is silent about a specific conversion rate of polysaccharide carbohydrates, they suggest a method comprising the same steps as the claimed method. It is presumed that methods having substantially the same steps are capable of performing substantially the same functions and delivering the same conversion rate. Therefore, the claimed limitations would have been obvious over the cited prior art.
Regarding Claim 5, Tolan et al. further teach that the solid fraction in the second enzymatic hydrolysis stage is re-suspended in a liquid at a solid concentration between about 3% and about 30% w/w (paragraph 0118). The range of about 3% to about 30% taught by Tolan et al. is largely overlapped with the range “10-40%” in the claim, thus rendering the claim obvious. See MPEP 2144.05.
Regarding Claim 10, Tolan et al. teach the feedstock and solid fraction are fed to the hydrolysis reactors in a batch mode (i.e. step by step) (Example 2, claim 43, paragraph 0064) or in a continuous mode (i.e. gradually) (see claim 44), thus rendering the claim obvious.
Regarding the claims 7, 26, 28 and 32, the method of Tolan et al. incorporated by Foody comprises diluting/mixing the pretreated feedstock/plant-based raw material or solid fraction with water or an aqueous solution (comprising enzymes) before the first or second enzymatic hydrolysis of the raw material or feedstock is carried out, as indicated above.
Regarding Claims 29 and 30, Tolan et al. teach the solid and liquid contents in the hydrolysis make-up tank “60” are mixed with an agitator/impeller “100” to form a mixed slurry “10” of the feedstock and aqueous enzyme solution, then to be pumped to the hydrolysis reactor (page 26/lines 26-30, page 34/lines 12-22, Figs. 1A and 1B); and Tolan et al. further teach the mechanical agitation is carried out during the enzymatic hydrolysis reaction, and the active mixing within a mixed hydrolysis tank is achieved by impellers (paragraph 0110: last 4 lines). The mixing action of agitator/impeller in the mixing stage in the method of Tolan et al. generate a shear force, which causes the solid content to be suspended in the liquid solution. It would have been obvious for the shear force to be sufficiently strong in the method of Tolan et al. so as to bring the solid and liquid contents into a homogenous mixture and disintegrate the solid, because the enzymatic hydrolysis requires enzymes to contact the surface of solid feedstock and then bind to the solid feedstock, as taught by Tolan et al. (para 00113); and the homogenous mixture and disintegrated solids would facilitate contacting and binding of the enzymes to the solid surface of the feedstock slurry of Tolan et al.
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention.
Claims 1, 5, 7-10, 13, 26, and 28-32 are rejected under 35 U.S.C. 103 as being unpatentable over Tolan et al. (WO 2007/147263, 2007, cited in IDS) and Foody (US Patent No. 4461648, 1984, of record, incorporated by reference by Tolan et al.), as applied to Claims 1, 5, 7-10, 13, 26, 28-30, and 32, further in view of Dasari et al. (Applied Biochemistry and Biotechnology, 2007, Vol. 136-140, pages: 89-300, of record), as evidenced by Tolan-2 et al. (US 2010/0184151, 2010, of record) and Particle Size Conversion Table (retrieved on 4/19/2024 from the Sigma-Aldrich website, of record). It is noted that the disclosure of Foody is a part of the disclosure of Tolan et al., since Foody is incorporated by reference to Tolan et al., as indicated above.
The teachings of Tolan et al. incorporated by Foody are described above.
Regarding Claim 31, Tolan et al. do not expressively teach the pretreated plant-based raw material includes fine particles smaller than 0.2 mm. The example 1 of Tolan et al. teach the plant based raw material has a solid particle size of 20 mesh (page 34, para 00130/line 2), a value equivalent to 0.84 mm or 840 mm, as evidenced by the Particle Size Conversion Table of Sigma-Aldrich (see page 2).
Dasari et al. studied the effect of varying particle sizes on enzymatic hydrolysis rates (glucose conversion rates) of red-oak sawdust (reading on the “wood based, cellulose based material” recited in Claim 1) by comparing the glucose conversion rates of enzymatic hydrolysis of sawdust, which has four different particle size ranges: 33 ~ 75 mm, 150 ~ 180 mm, 295 ~ 425 mm, and 590 ~ 850 mm; and they demonstrated that at lower particle sizes, there are higher enzymatic hydrolysis rates/glucose conversion rates (abstract, page 290/last para/line 1; Figs. 1-2). Specifically, particles size ranges of 150 ~ 180 mm and 33-75 mm (Note: they read on the claimed range “smaller than 0.2 mm”, given 1 mm = 1000 mm) had significant higher rates than the particle size ranges of 295 ~ 425 mm and 590 ~ 850 mm (ranges larger than 0.2 mm); and the lowest range 33-75 mm has the highest enzymatic hydrolysis rates (glucose conversion rates), and 50 - 55% more glucose was produced when the particle size of the sawdust was reduced from the range 590-850 mm to the range 33-75 mm, because smaller particles have larger surface area and more cellulose is accessible for enzymes to reach at a faster rate (Figs. 1-2, page 293/last para/lines 1-7, page 298/lines 2-8). Dasari et al. further teach that smaller particle sizes result in lower viscosities, the reduction in viscosity allows higher solid loading and reduced bioreactor size for large-scale process; and that particle size reduction provides a means for reducing long residence time required for enzymatic hydrolysis step in conversion of biomass to ethanol (abstract/last 9 lines, page 298/second half of conclusion).
It would have been obvious to modify the method suggested by Tolan et al. by reducing the particle sizes of the wood-based material (e.g. sawdust) so as to provide a pretreated wood-based material including fine particles smaller than 0.2 mm/200 mm (e.g. 33-75 mm) for the enzymatic hydrolysis reaction, thus obtaining a higher enzymatic hydrolysis rates/glucose conversion rates and higher amounts of glucose generated from enzymatic hydrolysis, as taught by Dasari et al. One of ordinary skill in the art would be motivated to do so, because Dasari et al. teach that reduction of particle sizes from the range 590-850 mm (encompassing 840 mm taught by Tolan et al.) to the range smaller than 0.2 mm/200 mm (e.g. 33-75 mm) increases the surface area of the wood-based material, such that more cellulose is accessible for enzymes and more amounts of glucose is generated from enzymatic hydrolysis of cellulose. Furthermore, Dasari et al. teach that application of wood-based material having particle sizes smaller than 0.2 mm for enzymatic digestion step have multiple advantages: including: reduction in viscosities of enzymatic hydrolysis solution, higher solid loading in enzymatic hydrolysis step (due to the reduction in viscosity), reduced bioreactor size for large-scale process, and reducing a residence time required for enzymatic hydrolysis step in conversion of biomass to ethanol. One of ordinary skill in the art has a reasonable expectation of success at modifying the method suggested by Tolan et al., because both the method of Tolan et al. and the method of Dasari et al. are directed to converting lignocellulosic material through enzymatic hydrolysis to fermentable sugars for ethanol production. The teachings of Dasari et al. about using wood-based material having smaller particle sizes are readily applicable to the method of Tolan et al. for increasing enzymatic hydrolysis rates.
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention.
Claims 1, 5, 7-10, 13, 26, and 28-32 are rejected under 35 U.S.C. 103 as being unpatentable over Tolan et al. (WO 2007/147263, 2007, cited in IDS) and Foody (US Patent No. 4461648, 1984, of record, incorporated by reference by Tolan et al.), as applied to Claims 1, 5, 7-10, 13, 26, 28-30, and 32, in view of Singh et al. (US 2016/0032339, Pub. Date: Feb. 4, 2016, effective filing date: Mar. 15, 2013, of record), as evidenced by Tolan-2 et al. (US 2010/0184151, 2010, of record). It is noted that the disclosure of Foody is a part of the disclosure of Tolan et al., since Foody is incorporated by reference to Tolan et al., as indicated above.
The teachings of Tolan et al. incorporated by Foody are described above.
Examiner notes that the claims 1, 5, 7-10, 13, 26, and 28-32 are alternatively rejected based on the combined teachings of Tolan et al. incorporated by Foody with Singh et al., for the reasons described below.
Regarding Claim 31 as well as the residence time of the first enzymatic hydrolysis recited in Claim 1, Tolan et al. do not teach the pretreated plant-based material comprises particles having a size less than 0.2 mm; and Tolan et al. do not teach a residence time in the low end of the claimed 8-12 hours for the first enzymatic hydrolysis stage, e.g. 8-10 hours. However, Tolan et al. teach a residence time range from about 12 hours to about 24 hours, which overlaps with the claimed range of 8-12 hours (as indicated above), wherein the lignocellulosic feedstock is partially hydrolyzed in the first enzymatic hydrolysis stage, specifically about 30% to about 80%, or about 30% to 60% of cellulose in the feedstock is converted to glucose or glucose oligomers/dimers (para 00105).
Singh et al. teach a similar method for hydrolyzing plant based biomass in two enzymatic hydrolysis stages and generating sugars/glucose from polysaccharide carbohydrates in the lignocellulosic biomass, where the method results in improved conversion of biomass to sugars/glucose (abstract), the method comprising: (i) pretreating the biomass with a high shear milling/mixing device to generate biomass particles with relatively uniform particle sizes; (ii) performing a first hydrolysis step by contacting the biomass with a catalyst to partially hydrolyze biomass components to sugars/glucose, thereby producing a mixture of solids and a liquid comprising sugars, wherein the catalyst is a saccharification enzyme and the biomass is a lignocellulosic biomass comprising wood-based plant material; wherein the contacting the biomass with the catalyst is conducted under conditions of high-shear agitation (mixing/milling) for enhancing mixing of the biomass with the catalyst and/or reducing particle sizes, and (iii) by using a centrifugation or filtration, separating the mixture into a liquid stream comprising sugars/glucose and a solids stream comprising solids absorbed with enzymes in a solid-liquid separation stage; and (iv) performing a second enzymatic hydrolysis step by incubating the solids stream associated with the enzymes (without adding additional enzymes) under conditions suitable to hydrolyze components of the solids to sugars/glucose, thereby producing additional sugars (abstract, paras. 0061-65 and 0067/lines 1-2 and 12-13, para 0034/lines 1-7, para 0088, 2nd half of para 0062, Claims 1, 3, 6-8, 26, and 29); wherein the separation of the solid stream from liquid stream is conducted after the enzymatic hydrolysis reaction in the first enzymatic hydrolysis step (by contacting biomass with enzyme/catalyst) has performed for a period of time, specifically from about 8 to about 10 hours, or for about 8, or for about 10 hours (i.e. a residence time of the first enzymatic hydrolysis of the biomass is about 8 or 10 hours, or in a range from about 8 to about 10 hours (para 0063/lines 7-15 from bottom) (Note: these residence time ranges substantially read on the claimed range “more than 8 hours less than 12 hours” recited in claim 1); wherein about 30% to 60% of glycan/cellulose in the biomass is converted to glucose in the first hydrolysis step (para 0063/last 6 lines); and the sugars/glucose converted from the biomass are used for ethanol production (para 20/lines 1-2, Claim 18); wherein the solid fraction is fed to the second enzymatic hydrolysis stage in a batch or continuous process (i.e. step by step or gradually) (paras. 0069/lines 6-8 from bottom, 0070/line 1, 0090/lines 2-5); and wherein the biomass contacted with enzymatic solution is completely mixed to ensure homogeneity, and the solid fraction (pellet) is diluted with a liquid for continuous enzymatic hydrolysis in the second stage (paras 0046/lines 3-6 and 8, 0047/lines 3-6 and 8, 0102/lines 6-7). Singh et al. further teach the particles used in their method have a relatively uniformed particle size from about 2 microns to about 200 microns (Claim 7), which is equivalent to a range from about 2 um to about 200 um, or a range from about 0.002 mm to about 0. 2 mm, which meets the limitation of “smaller than 0.2 mm” recited in Claim 31. Singh et al. further teach that enzymatic hydrolysis of lignocellulosic biomass is strongly affected by end-product inhibition, and the separation of the liquid stream from solid stream after the first hydrolysis step increases up to 50% more sugar converted from the biomass/glucan, compared to a method that does not comprises the separation step (paras 0003/lines 1-2, 0064/last 5 lines); and Singh et al. further teach another advantage of their method is to recycle the enzymes attached to the solid stream back to the enzymatic hydrolysis step, thus reducing the amount of enzymes that need to be added to fresh biomass and reducing the operation cost (para 0069/lines 6-15).
It would have been obvious to modify the method suggested by Tolan et al. by reducing the residence time of the first enzymatic hydrolysis stage to a time in the range from 8 to 10 hours (reading on claimed range of 8-12 hours) for conducting the first enzymatic hydrolysis reaction in the first enzymatic hydrolysis stage, wherein pretreated wood-based material is mixed with enzymes under the conditions of high-shear agitation for enhancing the mixing and reducing the wood material into particles relatively uniformed particle sizes, wherein the wood material comprises fine solid particles having a size smaller than 0.2 mm, thus improving conversion of the biomass to sugars/glucose, as taught by Singh et al. One of ordinary skill in the art would have been motivated to do so, because Singh et al. teach that application of these agitation and particle size conditions along with a shorter residence time range of 8-10 hours in the first enzymatic hydrolysis stage can effectively hydrolyze about 30% to about 60% of cellulose of lignocellulosic feedstock, which achieves the goal of the partial hydrolysis required by the method of Tolan et al. Furthermore, a shorter residence time would allow the enzymatic hydrolysis process to be completed more quickly, thus improving the efficiency of the method suggested by Tolan et al. One of ordinary skill in the art has a reasonable expectation of success at modifying the method suggested by Tolan et al., because both the method of Tolan et al. and the method of Singh et al. are directed to converting lignocellulosic material into sugar products, through a first and a second enzymatic hydrolysis stages, for ethanol production. The teachings of Singh et al. about the residence time and particle sizes used in the first enzymatic hydrolysis stage are readily applicable to the method of Tolan et al.
Examiner noted that teachings of Singh et al. further support that the newly added limitation of “an amount of carbohydrates being below 25 % by weight in the solid fraction …” recited near the end of the claim 1 is a well-known feature in the art. Specifically, Singh et al. further teach that 80% of glucans (i.e. polysaccharide carbohydrates) in the biomass are converted to soluble sugar/glucose through enzymatic hydrolysis in a total hydrolysis time ranged from not greater than 6 hours to not greater than 24 hours (para 0065, last 5 lines), which indicates that only 20% wt (100% - 80%) of the polysaccharide carbohydrates are remained in the solid fraction after enzymatic hydrolysis (Note: the amount of “20%” reads on the claimed range “below 25%”), thus further renders the claimed limitation to be obvious.
It is also noted that the teachings of Singh et al. about performing enzymatic hydrolysis reactions under high-shear agitation/mixing condition in first enzymatic hydrolysis stage further support the Examiner’s position that it is a routine practice in the art to mix lignocellulosic biomass with liquid solution for performing enzymatic hydrolysis reactions, previously indicated in the office action. Teachings of Singh et al. further render the limitations about the mixing stage and disintegrating solids with shear force in claim 1 and its dependent claims to be obvious.
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention.
Double Patenting
Claims 1, 5, 7-10, 13, 26, and 28-32 are rejected on the ground of nonstatutory obviousness-type double patenting as being unpatentable over Claims 1-11, 13-14, 16-19 and 21 of copending Application No. 18/800472 in view of Tolan et al. (WO 2007/147263, 2007, cited in IDS) and Singh et al. (US 2016/0032339, Pub. Date: Feb. 4, 2016, effective filing date: Mar. 15, 2013, of record), as evidenced by Tolan-2 et al. (US 2010/0184151, 2010, of record).
The claims of the ‘472 copending application are directed in part to a method for treating plant based raw material with an enzymatic hydrolysis, in which the plant based raw material is treated to form lignocellulosic material, and the lignocellulosic material is subjected to the enzymatic hydrolysis, wherein the method comprises: (a) pretreating the plant based raw material in at least one stage for forming the lignocellulosic material including over 80 % fine solid particles with a particle size smaller than 0.2 mm, wherein the pretreatment comprises treating the plant based raw material with a steam explosion treatment in presence of a chemical agent, the chemical agent being an acid (i.e. a combination of steam explosion and acid treatment); wherein the plant based raw material comprises wood based material; (b) subjecting the lignocellulosic material into the enzymatic hydrolysis in a enzymatic hydrolysis stage for enzymatically hydrolyzing the material to form a lignin based material; and (c) subjecting the lignin based material into at least one solid-liquid separation stage after the enzymatic hydrolysis and separating/recovering a lignin fraction and a soluble carbohydrate containing fraction; wherein the method comprises more than one solid-liquid separation stage; wherein the solid-liquid separation is made using filtration, centrifugal treatment or a combination thereof; wherein the soluble carbohydrate containing fraction is used as a source material in a process comprising fermentation, hydrolysis, enzymatic treatment, and/or manufacture of feed or food; wherein the lignin fraction is used as a source material in a process comprising hydrolysis, polymerization process, depolymerization process, manufacture of a composite material, and/or manufacture of binder.
The claimed method of the ‘472 application differs from the instant claim 1 in that the claims of the ‘472 application do not define the enzymatically hydrolyzing the plant-based material is performed in at least two enzymatic hydrolysis stages, wherein the residence time in a first enzymatic hydrolysis is more than 8 hour and less than 12 hours, and wherein the residence time in a second or later enzymatic hydrolysis is in the range of 22-48 hours.
The teachings of Tolan et al. and Singh et al. are described above.
It would have been obvious to perform the enzymatic hydrolysis of the wood-based material in at least two enzymatic hydrolysis stages in the method of the ‘472 application for enhancing hydrolysis efficiency and increasing yields of sugar production from the enzymatic hydrolysis process, wherein a solid fraction, obtained from a first liquid-solid separation stage after a first enzymatic hydrolysis stage that partially digests the lignocellulosic material, is supplied to a second enzymatic hydrolysis stage to be further hydrolyzed, followed by a second liquid-solid separation stage to separate liquid fraction from solid fraction containing lignin, as taught by Tolan et al. and Singh et al., One of ordinary skill in the art would have been motivate to do so, because sugars/carbohydrates present in the liquid fraction are competitive inhibitors of enzymes and cause product inhibition, and that the two enzymatic hydrolysis stages, involved with intermittent removal of the liquid fraction containing competitive inhibitors after the first enzymatic hydrolysis stage and supplying only the solid fraction to the second enzymatic hydrolysis stage, significantly improves yields of sugar production in the enzymatic hydrolysis process, and the two-stage enzymatic hydrolysis is more efficient, compared with an uninterrupted one-stage enzymatic hydrolysis, as supported by Tolan et al. and Singh et al. One of ordinary skill in the art has a reasonable expectation of success at performing the enzymatic hydrolysis of the wood-based material in at least two enzymatic hydrolysis stages in the method of the ‘472 application, because techniques for performing the two-stage enzymatic hydrolysis are well established in the art, as supported by Tolan et al. and Singh et al. Furthermore, both the method of the ‘472 application and the methods of Tolan et al. and Singh et al. are directed to enzymatically hydrolyzing wood-based material for producing soluble sugars/carbohydrates. Thus, the teachings of the cited prior art are readily adaptable to the method of the ‘472 application.
Regarding the residence time ranges of the first and second/later enzymatic hydrolysis stages recited in Claim 1, Tolan et al. teach the residence time in the first enzymatic hydrolysis stage is in a range from about 12 hours to about 24 hours for partially hydrolyzing the feedstock, which overlaps with the claimed range “more than 8 hours and less than 12 hours” in claim 1; and the residence time in the second enzymatic hydrolysis stage is in a range from about 12 hours to about 200 hours, specifically it can be 24, 30, 36, 42, or 48 hours, which either reads on or overlaps with the claimed range “22-48” hours” in claim 1. Furthermore, Singh et al. teach a residence time range of about 8-10 hours for the first enzymatic hydrolysis stage (reading on the claimed range), as indicated above. Thus, the claimed ranges would have been obvious over the combined teachings of the claims of the ‘472 application and cited prior art.
Regarding the limitations in claim 1 about supplying enzymes absorbed to a solid fraction to a second or latter enzymatic hydrolysis stage without adding additional enzymes, it is well known in that art that enzymes are adsorbed on the solid fraction after the first enzymatic hydrolysis stage, and hydrolysis of the solid fraction in the second enzymatic hydrolysis stage is effectively performed without an enzyme addition, as supported by Tolan et al. and Singh et al. Thus, the claim would have been obvious in view of the teachings of the cited prior art.
Regarding the limitations “the liquid after the first … stage comprising soluble C5 and C6 carbohydrates; recovering at least 50% of the soluble C5 and C6 … in the first … separation stage” and “the liquid fraction after the second or later enzymatic hydrolysis … comprising more than 80% by weight soluble C6 carbohydrate …” in the claim 1, these are well known features in the art when wood-based lignocellulosic material, pretreated specifically by steam explosion and acid treatment, is used as feedstock for the two enzymatic hydrolysis stages, as supported by Tolan et al. and evidenced by Tolan-2 et al. for the detailed reasons described above. As such, these limitations would have been obvious over the combined teachings of the